Position indicator



1962 c. BURCKHARDT ETAL 3,048,818

POSITION INDICATOR Filed July 16, 1958 5 Sheets-Sheet 2 Fig.5

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POSITION INDICATOR Filed July 16, 1958 5 Sheets-Sheet 5 Fig.10

9 2 1/ N S 5 N58 N S S N 8 2 P U ,U ,1 m w w a w "M m l l I l C k N .J N h N 9 W mm WV Mm 1 2 3 2 .2 2 w w w m, m X 3 R 1 3 9/ 7 9 1 H R R R R W R R R 2 4 W w 4 P M Q R 2 2 2 2 2 R R R R R R X h r X X X 0 2 4 6 8 4 y fi W? 7 7 T 1* 7 a m R R R R R 1 2 3 4 5 6 7 8 9 1 1 1 P P P P P P P P P P P U 11111111111 R R R R R R R R R R R R m M M X 3 ,5 7 9 H R d R R R R States Unite The present invention relates to a position indicator for the control of moved objects having only one degree of liberty, such as for example elevators.

The control of moved objects and particularly of cabins of automatic elevators requires a device providing information, in form of an electrical signal, on the position or place the elevator cabin takes within the elevator shaft. When a call is made from any floor an automatic means must be capable to use this signal to decide whether the elevator shall start to move and in 'what direction. Moreover this signal shall serve to fix the moment at which the braking shall begin in order to bring the elevator cabin to a stop at the predeterminated floor.

There are different mean known for reproducing the position of the elevator cabin within the shaft in form of an electrical signal. In many cases the position of the cabin is ascertained by so-called shaft commutators. These are electrical change-over switches mounted in the elevator shaft and commutated at the passage of the elevator cabin under the influence of a slide rail secured to the cabin. This system of shaft commutators has the advantage that the required electric circuits are easy to lay out and that the exact position of the cabin is immediately and correctly indicated also after an interruption in the current supply. There is, however, the disadvantage that these commutators are mounted in the shaft where their attendance is rather difficult and furthermore their number increases proportionally with the number of floors.

Also known are similar devices transmitting by mechanical means a precise indication about the position of the cabin within the shaft from the cabin to a switch apparatus arranged in the easily accessible engine room. This arrangement has the disadvantage that it requires a great expense.

The mentioned devices further have the draw-back that owing to their inertia they can only be used in connection with elevators having a relatively slow working speed. Further disadvantages of these devices are their noisiness and their mechanical wear. Electrical contacts also are often the source of disagreeable troubles.

Further known devices are controlled from the elevator cabin, for example by inductive pulse emitters, and reproduce the position of the cabin in an electrical storage means. The latter may be realized by a motor control device, by a relay arrangement, by a circuit with cold cathode tubes or the like. Such a solutionhas the substantial drawback that after an interruption in the current supply and more particularly if the cabin has been moved by hand the storage means is not capable to indicate the correct position of the cabin immediately. Moreover faulty switchings may occur when the cabin, upon actuation of the stop button, stops near the pulse emitter.

All above-numbered draw-backs may be eliminated by the use of position indicators characterized by magnetic storage elements having two steady states and adapted to be influenced in such a manner by magnetic actuating elements moved with respect to these storage elements that according to the direction of passage of an actuating elementthere is produced one of said states in the storage element whereby a member is provided for changing this state into an electrical signal.

. 3,048,818 Patented Aug. 7, 1952 Preferably the actuating element consists of a permanent magnet and is arranged stationary while the storage element is secured to the moved object.

The member for changing the state of a storage element into an electrical signal preferably includes magnetically saturable material comprising at least a winding, whereby the saturable material is influenced on the one hand by the storage element and on the other hand by an additional magnetic element in such a manner that the saturating effect increases in the one state of the storage element and decreases in the other state thereof.

A particularly appropriate arrangement is obtained when the additional magnetic element consists of a permanent magnet. In order to obtain optimum saturation and signal exploitation the magnetically saturable material is formed as a closed system.

The magnetic expense may be limited to a minimum when the magnet circuits of the actuating element, of the storage element and of the additional magnetic element form closed systems whereby the storage element serves as a common magnetic lead for all circuits.

Very often in addition to a short switching time the information emitter of moved objects is required to give the greatest possible precision on the local switching point. In order to meet this requirement the storage element is made symmetrical in moving direction with respect to the saturable material.

In place of a permanent magnet as compensating element there may be provided a winding acting on the saturable material.

Other features and advantages of the invention will appear from the description now to follow of preferred embodiments thereof, given by way of example and in which reference will be made to the accompanying drawings, in which:

FIGURE 1 shows a magnetic storage element with saturable material,

FIGURE 2 shows a magnetic storage element with semi-conductor,

FIGURE 3 shows a first embodiment of an arrangement,

FIGURE 4 shows a further embodiment of an arrangement,

FIGURE 5 is a view of a closed system position indicator,

FIGURE 6 is a section taken along the line VI--VI in FIGURE 5,

FIGURE 7 illustrates the saturable material with compensation by a winding,

FIGURE 8 illustrates an embodiment of an arrangement with position indicators for a six floor elevator, and

FIGURES 9 and 10 each show a portion of the circuit diagram belonging to the embodiment of FIGURE 8.

In FIG. 1 a stationary magnetic storing element is designated by the numeral 1, the end 2 of which element representing the south pole and the end 3 thereof the north pole. An additional magnetic element 4, for example, a permanent magnet, is connected to the end of the storing element 1 by means of a saturable material 5. In the magnetic element 4 one end 6 is designated as north pole and another end '7 as south pole. The winding 8 together with the saturable material 5 forms an inductance, of which the indu'ctivity represents a function of the condition of saturation. In the case shown, there is therefore produced the following magnetic flux: end 2end 3end 7end 6saturable material 5end 2. Thereby the magnetic flux in the material 5 is great, and the inductance of the winding 8 is correspondingly low.

If an AC, current source is applied over a loading re.- sistance to the terminals 18 of winding 8 a current may aoeasrs flow when the material is saturated owing to the low inductance in winding 8 and this current produces over the loading resistance a signal for the control. When the material is not saturated the inductance of winding 8 is high and no signal is produced at the loading resistance. A magnetic actuating element 9, for example, a permanent magnet, is arranged on a movable object, for instance an elevator cage, the north pole of said magnet facing the storing element 1. When the actuating element 9 moves past the storing element 1 from the position B, the direction of magnetization in the storing element 1 is changed, i.e. the end 2 becomes a north pole and the end 3 a south pole. This change in the direction of magnetization comes about as follows: The actuating element 9 exhibits a high coercive force due to its geometry. As soon as the lower portion of element 9 passes into the zone of the end 2, the magnetic flux of the element 9 is added to the flux in the storing element 1, whereby the south pole at the end 2 will be strengthened. However, when the actuating element 9 continues to move, the upper portion of element 9 also enters the zone of the end 2 as the element moves towards portion B. The flux of element 9, however, opposes the already described flux in the storing element 1 so that the end 2 becomes a north pole. In other words, the coercive force of the element 9 is high enough to reverse the polarity of storing element 1 as the north pole of element 9 approaches the north pole of element 1. Accordingly, the south pole is displaced in the direction towards the end 3 and remains there, even if the storing element 1 has passed beyond the eflect of the magnetic influence by the actuating element 9 i.e. when the actuating element 9 has arrived at the position B.

Upon movement of the actuating element 9 in opposite direction back to the position A the direction of magnetization changes again. The difference of the inductnce of winding 8 is used for the electrical signalling.

The direction of magnetization changes if the magnetic force of the actuating element 9 is sufficiently high and if this element is arranged at a small distance from storage element 1.

In FIG. 2 the saturable material is replaced by a semiconductor 11, for example, a resistor dependable on the magnetic field. The semiconductor 11, being influenced on the one hand by a storing element 14 and on the other hand by a magnetic element 15, comprises two electrodes 12 and 13 which are connected to a control device. In a manner similar to the one described in FIG. 1, the direction of magnetization in the storing element 14 is changed and influences the resistance of the semiconductor 11. This change, in the same manner as the change in the inductance of the winding 18, is used as signalling means for the control device.

FIGURE 3 illustrates an arrangement in which actuating elements 90, d, e, f are arranged at a stationary object 27, for example at a shaft wall along the path of the moved object 22, for example an elevator cabin, while the storage element is arranged at the moved object 22. The actuating elements 90, d, e, f, are arranged in such a way that alternatively the south pole and the north pole is turned toward the storage element 1 as it passes. In the represented position C the direction of magnetization of the storage element 1 is designated by O, i.e. the end 2 is the north pole and the end 3 the south pole. The storage element 1 moves from position C to position D. When passing the actuating element 90 the direction of magnetization of the storage element 1 changes into the state I i.e. end 2 becomes the south pole and end 3 the north pole. In the position E the storage element 1 is again in state 0, in the position F it is in state I. The sequence of the states thus is O-I-OI.

In FIGURE 4 the actuating elments 9g, h, i, k are also stationary and the storage element is arranged at the moved object. The sequence of the poles of the actuating elements in direction of the passing storage element 14 is N NS-S. It is visible that, with the direction of moving 16, in the position H the state of the storage element is I, while in the direction of travel 17 the occurring state is O. In the field K the conditions are analogous but with reversed states. Other combinations of the sequence of the states may be chosen whereby the latter serve to determinate the position and the direction of travel of the moved object.

FIGURE 5 illustrates a position indicator with closed magnet systems, in which a storage element 20 of magnetizable material has the form of a loop whereby the middle axis VI-VI of a saturable material 23 extends exactly in the longitudinal middle extension of the loop. The storage element 20 is secured by fastening means 21 to a moved object 22, for example to an elevator cabin. The saturable material 23 is inserted between the ends 30 and 31 of the storage element. In order to obtain the greatest possible concentration of the lines of fiuxof the saturatable material 23 the latter has the shape of a toroid. The saturable material 23 provided with a Winding 24 is located is an insulating casing 25 secured to the moved object 22. In order to render sensitive the saturable material 23 to the-direction of the magnetic flux between the two ends of the storage element 20 an additional magnetic element 26, for example a permanent magnet, is secured to the moved object 22.

At the stationary guiding portion 27 of the moved object 22, for example at the shaft wall of an elevator, actuating elements 28, preferably permanent magnets are secured in the manner described in FIGURE 4.

In place of the additional magnetic element 26 it is possible to provide, as shown in FIGURE 7, a magnetization winding 29 on the portions 30 and 31 of the storage element 20. The winding 29 may also he slipped directly over the saturable material 23. In the position indicated in FIGURE 5 the end 30 of the storage element 20 is a north pole and the end 31 a south pole. The flux issuing from the ends 30 and 31 of the storage element 20 is supported by a north pole '32 and a south pole 33 of the additional magnetic element 26 and consequently the saturating eflect is increased in one state of the storage element 20 and reduced in the other state.

If the storage element 20 passes an actuating element 28 in direction of the arrow P the ends 36 and 31 change their polarity. The additional magnetic element 26 compensates the flux between the ends 30 and 31 and consequently the saturable material 23 is not saturated. The magnetic forces and the dimensions of elements 20, 23 and 26 are chosen so that in the position shown in FIG. 5 the element 23 is saturated. If in this case an A.C. current source is connected with the winding 24 (over a load resistance) a current will flow due to the low inductance of said winding, which current produces a signal for the control. If, on the other hand, the magnetic force of actuating element 28 is sufliciently high and the distance between this element 28 and the storage element 20 is sufliciently small the direction of magnetization of element 20 is changed when the element 20 passes the element 28 in the direction of arrow P. The additional element 26 compensates the flux between the ends 30 and 31 and the element 23 is desaturated. If an AC. current source is now connected to the winding 24 (over a load resistance) practically no current will flow (due to the high inductance of winding 24) and thus no signal will be produced for the control.

For stabilizing and compensating purposes, further ad ditional magnetic elements may be provided at the storage elements 20.

FIGURE 8 illustrates an arrangement of the position indicator in a six floor elevator. The cabin 40 is connected by cables 41 over a driving drum 42 with a counterweight 43. The driving drum 42 is driven by the engine M0. The cabin 40 and the counterweight 43 move in a shaft 45. The floors are indicated at a, b, c, d, e, f. The cabin carries the storage elements g, h, i, k. The shaft is divided into zone X1-X11, whereby the zones X1, X3,

X5, X7, X9, X1 1 constitute braking zones. The zones X2, X4, X6, X8, X are intermediate floor zones. The paths of the storage elements g, h, i, k are designated by g, h, i, k.

In order to get on with the smallest possible number of position indicators the zones X1.-X111 are numerated in the present example progressively according to the cyclic binary number system, i.e. the zones X1 with 0001, X2 with 0011, X3 with 0010 etc., as shown in FIGURE 8. In the represented embodiment the cabin is in the floor c, that is, in zone X5, to which is assigned the cyclic binary number 01 11. In this zone the storage elements g, h, i, k, correspond to the state 0111.

If the cabin 40 moves, for example downwardly from floor c and enters from zone X5 into the zone X4, the actuating element 46 on path g produces with its south pole facing the storage element g a change into the state 0. At the transition from zone X4 to zone X3 the actuating element 47 produces the change of the storage element i from state I to state 0. Analogously upon further travel of the cabin the corresponding states are obtained as they are indicated in FIGURE -8.

In FIGURES 9 and 10 it is shown by means of diagrams how the information of the position indicators g, h, i, k are used for a control of the elevator. The following designations shall be used:

MB-braking magnet MV-magnet for actuating the shaft door lock RSa-RSf-fioor relays RlU-switch for downward travel R2U-switch for upward travel R1PR4P-position relays R1X-R11X-zone relays R1V-pre-control relays for downward travel R2Vpre-control relays for upward travel DH--stop button KTa-KTf-door contacts KVa-KVf-locking contacts KMB-contact at the braking magnet DCa-DCf-push button in the cabin Daa-Dafpush button in the floors.

In FIGURE 9U, V, W designates a three-phase mains feeding over main switch JHth and the switches RlU and R2U the engine M0. Leads 101 and 1000 are fed over a transformer Tr. The stop button DH and the door contacts DTa-DT are mounted between the lead 101 and a lead 129.

In the position shown in FIGURE 8 the cabin is in floor c to which is assigned the state 0111. This state is reproduced by means of the storage elements g, h, i, k with the corresponding relays RIP-R4P (FIGURE 10) at the zone relays R1X-R11X. For the mentioned case the relays RIP, -R2P, R31 are excited While relay R4'P is currentless. Consequently contact R4P1 is open. Relay RX5 is excited over the contacts R4P2R3P4R1P7. With the zone relays R1X-R11X and the floor relays RSa-RSf the travel directions corresponding to the different calls are determinated at the pre-control relays R1V and RZV.

A call, for example an outside call in floor a, is executed as follows: Outside push button Daa closes, relay RSa is excited. Contact RS112 closes and excites over contacts R1X2 and R1X1 the pre-control relay R=1V. The relay RSa becomes self-supporting over contacts R1V3 and RS111. Simultaneously the locking magnet MV is excited over the contact R1V2. The locking contact KVc closes. The switch R-1U is excited over the contacts KVa to KVf-RSVl-RZUI and starts the engine M0 and thus brings the cabin 40 to downward movement.

The stop order is given to the cabin only after the relay RlV drops over the open contacts R1X2 and R lXl as at the transition from the zone X2 to the zone X1 which corresponds to the braking zone of floor athe relay R1X is excited over the contacts R4P2-R3P3 R2P6--R1P11 in accordance with the positions of the relays R1P-R4 P which is equal to the cyclic binary number of the zone X1. Contact R1X1 opens and the relay R1V releases. The contacts R1V1, R1V2 and R1V3 open, switch R1U drops and separates the engine M0 from the mains. The magnets MV and MB become currentless, the mechanical brake engages and the door locking is liberated. Floor relay RSa drops.

Other travel orders are executed analogously.

We claim:

1. A position indicator for controlling moved objects with only one degree of liberty, comprising magnetic storage elements having two remanent steady, polarization states, magnetic actuating elements movable with respect to said storage elements and operatively disposed with respect to said storage elements to produce, when passing a storage element in one direction, one of said remanent, steady, polarization states and, when passing in the opposite direction, the other of said remanent, steady, polarization states, and means to indicate at least one of said states as an electrical signal.

2. A position indicator as claimed in claim 1, in which the actuating elements are stationary and the storage elements are movable relatively thereto.

3. A position indicator as claimed in claim 1, in which the actuating element, of the storage element and the additional magnetic element form a closed magnetic circuit, the storage element constituting a common magnetic lead for all such circuits.

4. A position indicator as claimed in claim 3, in which the additional magnetic element is a winding acting on the saturable member.

5. A position indicator for controlling moved objects with only one degree of liberty, comprising magnetic storage elements having two remanent, steady, polarization states, permanent magnets constituting magnetic actuating elements movable with respect to said storage elements and producing, when passing a storage element in one direction, one of said remanent, steady, polarization states and, when passing in the opposite direction, the other of said steady states, and means for indicating said states as electrical signals.

6. A position indicator for controlling moved objects with only one degree of liberty, comprising magnetic storage elements having two remanent, steady, polarization states, magnetic actuating elements movable with respect to said storage elements and producing, when passing a storage element in one direction, one of said remanent, steady, polarization states and, when passing in the opposite direction, the other of said steady states, and means for indicating said states as electrical signals, an additional magnetic element, said means including a magnetic saturable member and at least one winding associated therewith, said means being operatively associated with a storage element and said additional element so that the saturable member is influenced on the one hand by the said storage element and on the other hand by said additional magnetic element so that the saturating effect increases in one remanent state of the storage element and decreases in the other remanent state.

7. A position indicator as claimed in claim 6, wherein the said additional magnetic element is a permanent magnet.

8. A position indicator as claimed in claim 6, in which the magnetically saturable member is a closed loop.

9. A position indicator as claimed in claim 6, in which the storage element is symmetrical with respect to the longitudinal middle axis of the saturable member.

10. A position indicator for control-ling moved objects with only one degree of liberty, comprising magnetic storage elements having two remanent, steady, polarization states, magnetic actuating elements movable with respect to said storage elements and producing, when passing a storage element in one direction, one of said remanents, steady, polarization states and, when passing in the opposite direction, the other of said remanent, steady, polarization states, means for indicating said states as electrical signals, an additional magnetic element operatively associated with said means, said means including a semi-conductor comprising at least two electrodes and having electrical properties adapted to change under the influence of a magnetic field such that the semi-conductor is influenced on the one hand by a storage element and on the other hand by said additional magnetic element so that the magnetic field acting on the semi conductor is increased for one remanent state of the storage element and reduced for the other remanent state thereof.

11. A position indicator according to claim 10, wherein the said additional magnetic element is a permanent magnet.

References Cited in the file of this patent UNITED STATES PATENTS 2,532,231 Jarvis Nov. 28, 1950 2,883,108 Thornton Apr. 21, 1959 FOREIGN PATENTS 16,839 Holland Mar. 15, 1927 482,495 Germany Mar. 29, 1923 868,503 Germany Ian. 15, 1953 

